When the United States has been through periods of deep economic anxiety before, the populist movements that mobilize ordinary citizens against an empowered elite have typically pushed the national agenda to the left. A century ago, they backed the idea of a graduated income tax.

But now, at a time of high unemployment, record foreclosures, a significant jump in poverty, and concerns about a possible new recession, populist outrage has largely focused on government as a problem rather than a source of economic cures.

Political analysts cite several reasons. Some of the activity is a backlash against the president. Since President Obama is a Democrat, it’s more likely that opposition will rise up on the right.

Another factor is that the nation’s top priority, a dearth of jobs, is hard to fix, with neither the left nor right offering solutions that most of the public view as clear-cut winners. It’s possible that many tea party supporters are attracted to the movement because it provides a clear target at which to vent – bloated government – even if that may not be the cause of the problem. Frank Newport, editor in chief of the Gallup polls, uses this analogy: “If you’re mad at work, you come home and kick the cat.”

A third reason, some say, is that the right has found ways to steadily deepen its roots, while the left has seen key institutions such as labor unions wither.

It’s a development decades in the making. Notably, Ronald Reagan steered the country toward greater skepticism of government and a stronger embrace of free-market economics. A parallel rise of conservative think tanks, as well as the political influence of Christian-right colleges and advocacy groups, helped spread this message.

By the time activists latched on to a 2009 rant by CNBC’s Rick Santelli, who raised the idea of a modern-day tea party, the field had been prepared. The American right knew who its enemy was, and conservative politicians, donors, and media – notably Fox News – lavished attention and support on tea party rallies to help the movement grow.

To be sure, the left has its own parallel groups and backers. But their clout has been diminishing, argues Mr. Kazin. Private-sector labor unions have been in steady decline, he notes, and other liberal groups have changed so they cater more to middle-class social causes (the environment, same-sex marriage) than to the economic concerns of ordinary workers.

Occupy Wall Street could become a remedy to that for the left. The Wall Street protests in part express the frustration of a “lost generation” of young Americans facing high student-loan debts and grim job prospects. But they have rallied support from liberal groups ranging from labor unions to MoveOn.org, which added a “virtual march on Wall Street” to its website on Oct. 5. Film celebrities like Michael Moore and Susan Sarandon have lent their voices.

Mr. Vena, who attended a recent rally against Bank of America in Boston, lives in Burlington, Mass., a middle-class suburb outside the city. He says he’s not a protester by nature, but has grown deeply concerned about America’s future.

It doesn’t help that two of his sons, with college degrees in economics and business, are unemployed, and that he has recently had his own bout of joblessness.

If the economic problems aren’t addressed, he says, “I actually worry about a revolution coming in 2020 or later.”

What the Wall Street protests show most clearly, perhaps, is that the dissatisfaction that is fueling the right is now also starting to drive the left.

“Obama just flat-out failed to deliver on the most important promise of his campaign,” says Cenk Uygur, host of Current TV’s “The Young Turks,” a show on politics. “He said we are going to fundamentally change the way Washington works. He hardly tried.”

But so far, the Wall Street protests have targeted corporate influence without providing a clear vision of what they want. The tea party movement, by contrast, has focused from the onset on shrinking the size of government and low taxes. In that way, it parallels past populist movements – even if it is conservative in orientation.

H.W. Brands, a historian at the University of Texas at Austin, sees the current US situation as analogous to the late 1890s, when the People’s Party became a force in American politics.

Now, as then, Americans were anxious amid economic and social upheaval. Today, Americans are troubled by the implications of globalization. Back then the nation was in the throes of the Industrial Revolution and a strong populist movement emerged from rural voters.

“The world was changing out from under them,” Mr. Brands says. “The farm ... had given way to the factories. [Populism] was as much an emotional response as it was an economic response.”

And now, as then, the populists focused on simple answers to complex challenges. In the 1890s, the People’s Party’s answer was “free silver” – a proposed departure from the gold standard, which was seen as harming indebted farmers, to allow coinage of silver, too. Today, it is federal spending cuts.

But just as free silver was at best a partial answer to the challenges facing late-19th-century farmers, federal deficit reduction is not a fully formed plan for restoring economic growth, Brands says.

Measuring the extent of the conservative populist surge since 2009 is difficult. On one hand, Republicans used it to win historic gains in the House of Representatives in the 2010 midterm elections. But Republicans in Congress are as unpopular as Democrats, polls find.

Other polls show Americans are more likely to say they disapprove of the tea party than approve. A Gallup poll in August found 25 percent of Americans call themselves tea party “supporters,” while 28 percent see themselves as opponents and 42 percent said neither.

But the tea party has clearly given the right more purpose and energy. Occupy Wall Street could be an answer to that, and supporters of the protests note parallels to the early days of the tea party movement – beginning with grudging media coverage.

“There’s been thousands of people across the country participating in this,” says Mr. Uygur. The news media have been “weirdly derisive and dismissive” of protests on the left, he says, even when “the same numbers of people show up” as to some tea party events.